Mercurial > pub > bltoolkit
diff Source/Data/Linq/Builder/IntersectBuilder.cs @ 0:f990fcb411a9
Копия текущей версии из github
author | cin |
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date | Thu, 27 Mar 2014 21:46:09 +0400 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Source/Data/Linq/Builder/IntersectBuilder.cs Thu Mar 27 21:46:09 2014 +0400 @@ -0,0 +1,56 @@ +using System; +using System.Linq.Expressions; + +namespace BLToolkit.Data.Linq.Builder +{ + using BLToolkit.Linq; + using Data.Sql; + + class IntersectBuilder : MethodCallBuilder + { + protected override bool CanBuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) + { + return methodCall.Arguments.Count == 2 && methodCall.IsQueryable("Except", "Intersect"); + } + + protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo) + { + var sequence = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0])); + var query = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[1], new SqlQuery())); + var except = query.SqlQuery; + + sequence = new SubQueryContext(sequence); + + var sql = sequence.SqlQuery; + + except.ParentSql = sql; + + if (methodCall.Method.Name == "Except") + sql.Where.Not.Exists(except); + else + sql.Where.Exists(except); + + var keys1 = sequence.ConvertToSql(null, 0, ConvertFlags.Key); + var keys2 = query. ConvertToSql(null, 0, ConvertFlags.Key); + + if (keys1.Length != keys2.Length) + throw new InvalidOperationException(); + + for (var i = 0; i < keys1.Length; i++) + { + except.Where + .Expr(keys1[i].Sql) + .Equal + .Expr(keys2[i].Sql); + } + + return sequence; + } + + protected override SequenceConvertInfo Convert( + ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo, ParameterExpression param) + { + return null; + } + } +}